please help me??? ROVER 216?

I assume that the 'alarm' is a quiet, internal two tone alternating alarm?
If it is, it's caused by one of two things.
Either you are using an ignition ket that has no rover electronic fob with it, or the fob has flat batteries.
I note that you had to use the key to open the car, and that suggests that the batteries are dead.
I think the correct one is a 2032 flat circular 3 volt cell. You can get them in Asda, or motoring shops etc.
Insert the battery, then you'll need to programme the fob again.
Do this by inserting the key in the ignition, turn on, then press the 'open door' button for about 10 seconds.
Turn the ignition off, get out of the car, and see if the fob locks and then re-opens the car. If it does, your engine will probably start.
Regards,
Wyn

Wyn
July 2007